Fuel injection pump



Jan. 19, 1954 w. FRIEDLANDER 2,666,391

FUEL INJECTION PUMP I Filed June 4, 1951 2 Sheets-Sheet l GSL j i 35X 33 w. FRlEDLANDER v 2,666,391 FUEL INJECTION PUMP Jan. 19, 1954 2 Sheets-Sheet 2- Filed June 4, '1.951

FIGB.

Patented Jan. 1.9, 1.954

2,666,391 ICI?.`

FUEL INJECTIO-NsIUMPv William Friedlander, Westminster, London, England', assigner to Mono-Cam Limited, Westminster, London, England', a. company of Great.

Application June 4, 1951Serial-No. 229,792

Claims priority, applicationY Great Britain June 6, 1950 4 Claims.

This invention relates to'fuel injection-.pumpsl for internal combustion engines, particularlyr though not exclusively, compression-ignition, engines. It is concerned with improvements. 1n pumps of the kind (hereinafter referred' to as the kind specineao in which the eeecuve iength of the delivery strokes of the respective pistons is similarly controlled simultaneously for al1 the pump `cylinders by actuation of a Icommon regulating member which adjusts, for each cylinder, the position of an element which determines at what point in the delivery stroke fuel will be spilled from the cylinder into a chamber or passage in communication with the inlet side. of the pump, the fuel tank or a like low-pressure region, the common regulating member being a` Y plate or disc and the elements adjusted thereby being sleeves tted over the pump pistons or plungers to control the outlet ends of spill passages which run through the pistons or plungers from the operative end faces thereof to the cylindrical surfaces thereof. Y

In such pumps it is desirable, from the point of View of ease of manufacture, that the sleeves shall be positioned transversely of their axes Vsolely by their eng-agement with the pump pistons or plungers While it is essential that there shall be no appreciable axial motion of the sleeves relative to the common regulating member once they have been adjusted correctly in relation thereto.

A pump of the kind referred to is described in the specification of Letters Patent No. 2,517,483 and the means for mounting the sleeves in the common regulating member which is there employed aifords these desirable and essential features but is somewhat expensive tomanufacture and requires careful adjustmentk by relatively skilled operatives.

The object of the present invention is to pro-` vide an improved and simpler arrangement;` whereby these disadvantages may bev avoided.

According to the invention, in a fuel injection pump of the kind specified, theV sleeves are located in the -common'regulating member so that they are all positioned by two common opposed axially spaced surfaces provided on the member while beingv free to adjust themselves transversely of their axes by sliding between these surfaces.

It is preferred to construct the regulating member with two parts each aifording one of the surfaces and adapted to be secured together with the interposition of spacing elements, one of the parts having a niunber of apertures each arranged to accommodate one of the sleeves with radial clearance and each sleeve having a flangev of larger transverse dimensions than` thecorre.-

- spending aperture and. adaptedtol be: engaged;V

axially in relation thereto `the line I-IY of Fig. 3 showing equal to the axial dimension of a` spacing ele.-

ment so that the flange will not. be gripped between the positioning surfaces when the parts. are. secured together. dimensions may be very small, so that the ange is merely slidable between the surfaces,r or mayV be somewhat larger, so that shims may be interposed between the flange and one or both of the positioning surfaces to alcrd a rangeof axial adjustment to the sleeve while still ensuring that'it. can. only slide between the surfaces. of the shims without moving axially relative to thev regulating member. By the last-mentioned arrangement provision may be made for effecting. axial adjustments of the several sleeves to differ ent degrees.

In order that the invention may be clearly understood, an example of the way in which it may be carried into effect will now be described in greater detail withv reference to the accompanying drawings.

In this example, the pump chosen for illustrative purposes is constructed substantially in accordance with the invention forming the subject matter of. Letters Patent No. 2,517,483 but the present invention may be applied also to other constructions of pumps. of the kind speci'- fied above without difliculty.

In: the drawings:

Fig. 1A is a upper part of a section taken on thefline I-I of Fig. 3 ay part being broken away,

Fig. 1B is the lower part of this section,

Fig. 2 is a fragmentary sectional view taken on the regulating member of Fig. 1A and illustrating a modification employing shims, and

Fig. 3 is an under plan view of Fig. 2 but with theshirns omitted.-

The pump, as shown in Fig. 1A, comprises a generally cylindrical housing i having a camV ingv there are the appropriate pump cylinders 5;

disposed around and parallel with the `axis of the housing and each communicating through a delivery valve 6l with the corresponding deliver-yH connection 4. The cylinders 5 and the respective pistons or plungers 'i' are all identical and only one set of these parts need be described here. The; cylinderV wall is formed with radial bores 8l near its outer endr and is surroundedv at this locaF tion by an annular fuel supply passage 9." This; is,` linfpermanent.' communication with a.. central@` The difference in these annular chamber l (supplied from an inlet not shown) formed by a recess in the cylindrical Wall of the enlarged inner end il of an axial bore l2 in the housing l provided to admit the passage of a stem i3 attached to a common regulating member hl, i5, l, located in the spill chamber 3. The regulating member serves to position controlling sleeves Il which are a close sliding lit on the pistons l Working in the cylinders 5. Each piston l is a close sliding fit in its cylinder 5 which projects, with play, part-Way into an aperture i8 in the regulating member, the corresponding controlling sleeve being mounted on the latter in such manner that it may move laterally (e. g. radially or circumierentially of the member) Without being capable of any appreciable motion relative to the member in the axial direction.

The piston l continues beyond the sleeve Il, through an over-size hole lil in a partition member 2t secured transversely of the spill chamber 3, to be surrounded by a compression spring 2| bearing at its ends upon the partition member 2G and upon a collar 22 secured on the end oi the piston, respectively. This end of the Vpiston l bears upon one end of a reciprocable push rod 23 the other end ci' which (see Fig. 1B) carries ya roller 25; cli-operating with a face cam 25 rotatable Within the cam member 2 by means of a shaft 2li extending axially through the end of the housing l to be driven from the engine cra-nkshait at an appropriate speed.

Centrally oi the partition member 2t (see Fig. 1A) is formed an axially extending cylindrical Wall 2l surrounding a liner 28 Within which slides a spigot part 2t secured on the regulating membei' lll. Axial adjustment oi this member varies the position oi the controlling sleeves l1 relative to the length of the pistons l which are formed with axial bores iii leading from their operative end faces to radial bores 3l the opening o which occurs as they move out of the controlling sleeves Il during the delivery strokes of the respective pistons.

The pump thus ar described operates in exactly the same manner as that described in specication No. 2,517,483 rotation ci the face cam 2b causing reciprocation of the pistons l and the consequent delivery, per Working stroke, of a quantity of iuel determined by the spacing for the time being or the controlling sleeves il from the cylinders 5. u

According to this invention the regulating member made in two parts, one part constituting a disc-like element lil formed with a thickened edge I5. and the other part being a ring l5 of the same or substantially the same external diameter as the rst part. The ring ifi is clamped to the thickened edge iii ci the disc-like element i4 and has apertures 32 termed therein, each aperture being traversed by the corresponding plunger 1 of a diameter somewhat larger than that of the main body of the sleeve il which is slidably tted on that plunger. Each sleeve il has'a ange 33 at its one end which is larger in diameter than the .respective aperture 32 and all the sleeve anges 3S are made or the same axial thickness.

The ring part i@ of the regulating member is arranged to be attached to the disc part i4 by bolts te or like With the interposition of spacers ci axial length equal to or somewhat greater than the axial thickness of the sleeve flanges 33. See Fig. 1A for an example of the case where the spacers are of an axial length equal to the axial thickness or" the sleeve flanges 33 and Fig. 2 for an example of the case in which the axial length of the spacers 35 is greater than the axial thickness of the. sleeve ilanges 33, shims being provided to prevent axial movement of the sleeves.

ln the assembly of the parts, Vthe disc ld is first placed in position with the plungers 1 extending therethrough, the sleeves Il are slid ilange-rst on to the respective plungers 1, and the ring l5 is threaded over the latter so that the main bodies of the sleeves il are `acccunmodated in the apertures 32 in the ring iii. The latter is then secured to the disc It, with the interposition of the spacers 35 and the distance between the adjacent surfaces of the ring it and thickened edge l5 of the disc I4 is then such in the case of Fig. 1A, that the'flanges 33 of the sleeves Il, though capable of moving laterally between these surfaces, cannot move to `any appreciable extent in the axial direction relative thereto.

In order that the required precision may be secured, the positioning surfaces of the ring it and disc is are preferably ground true, as are also the zzo-operating faces of the sleeve flanges 'E3 and of the spacers 35.

Where adjustment of one sleeve relative to another in the axial direction may be required, it is preferred to make the spacers 35 of an axial length greater than that of the sleeve flanges 33 (see Fig. 2) by an amount corresponding to the maximum adjustment that can be required. In this case, the excessive axial play 'that would otherwise be allowed tothe sleeve flanges 33 between the positioning surfaces is taken by the insertion of annular shims SES between the respective faces or the flanges 33 and the positioning surfaces. These shims are individual to the respective sleeves so that by appropriately selecting their thicknesses, the several sleeves may be diierently positioned axially with respect to the regulating member.

It will be appreciated that the manufacturing operations required for producing the several Y parts are or" a simple character yet capable of performance with a high degree of precision. llurther,` the assembly and adjustment or these parts is a simple matter.

What claim is:

i. A fuel injection pump comprising a pump housing, a plurality of pump piston and cylinder assemblies located within the housing with their axes parallel to each other, each piston being reciprocable in a cylinder, a cam for reciprocating the pistons, a spill passage in each piston, a spill chamber formed in the housing, an element slidable axially on each piston to determine by its axial position the point in the stroke of the piston at which the spill passage therein will be placed in communication with the spill chamber, a regulating member mounted Within said spill chamber and displaceable in a direction parallel to said axes, a first abutment suriace formed on said member to extend normal to said axes, a nrst locating surface associated with each of said elements and arranged to slidably engage said first abutment surface, a second abutment surface formed on said member and spaced from said iirst abutment surface in a direction parallel to said axes, and a second locating surface associated with each of said elements and arranged to slidably engage said second abutment surace,

` said rst and second abutment surfaces engaging said nrst and second locating surfaces respectively to control said axial position of said elements Whilst permitting the latter to adjust themselves in a direction normal to said axes by said rst and second locating surface sliding over said first and second abutment surfaces respectively.

2. A fuel injection pump comprising a pump housing, a plurality of pump piston and cylinder assemblies located within said housing with their axes parallel to each other, each piston being reciprocable Within a cylinder, a cam for reciprocating said pistons, a spill passage in each piston, a spill chamber formed in the housing, an element slidable axially on each piston to determine by its axial position the point in the stroke of the piston at which the spill passage therein will be placed in communication with the spill chamber, a first part mounted within said spill chamber and displaceable in a direction parallel to said axes, a first abutment surface formed on said first part and arranged to extend normal to said axes, a second part mounted within said spill chamber and displaceable in a direction parallel to said axes, a second abutment surface formed on said second part and arranged to extend normal to said axes, spacing means intern posed between said first and second abutment surfaces to maintain these latter in spaced parallel relationship, means for securing said first and second parts and said spacing means together to constitute a regulating member, a rst locating surface associated with each element and arranged to slidably engage said first abutment surface, a second locating surface associated with each element and arranged to slidably engage said said second abutment surface, said elements being held against displacement relative to said member in a direction parallel to said axis by engagement of said rst locating surface with said first abutment surface and said second locating surface with said second abutment surface respectively whilst being capable of adjusting themselves in a direction normal to said axis by said iirst locating surface sliding over said rst abutment surface and said second locating surface sliding over said second abutment surface respectively.

3. A fuel injection pump comprising a pump housing, a plurality of pump and cylinder assemblies located within said housing with their axes parallel to each other, each piston being reciprocable Within a cylinder, a cam for reciprocating said pistons, a spill passage in each piston, a spill chamber formed in said housing, a sleeve element slidable axially on each piston to determine by its axial position the point in the stroke of the piston at which the spill passage therein Will be placed in communication with the spill chamber, a first part mounted within said spill chamber and displaceable in a direction parallel to said axes, said rst part Abeing formed with a number of apertures each arranged to accommodate one of said sleeve elements with clearance, a iiange formed on each of said elements of larger transverse dimensions than the corresponding aperture, and a second part mounted in said spill chamber and displaceable in a direction parallel to said axes, a first abutment surface formed on said first part to extend normal to said axes, a second abutment surface formed on said second part to extend parallel to said first abutment surface, spacing means interposed between said rst and second abutment surfaces to maintain these latter in spaced parallel relationship, means for securing said first and second parts and said spacing means together to constitute a regulating member, a first locating surface formed on said flange and arranged to slidably engage said rst abutment surface, a second locating surface formed on said iiange and arranged to slidably engage said second abutment surface, said sleeve elements being held against displacement relative to said member in a direction parallel to said axes by engagement of said first locating surface with said rst abutment surface and said second locating surface with said second abutment surface respectively whilst being capable of adjusting themselves in a direction normal to said axes by said iirst locating surface sliding over said rst abutment surface and said second locating surface sliding over said second abutment surface respectively.

4. A fuel injection pump comprising a pump housing, a plurality of pump piston and cylinder assemblies located within said housing with their axes parallel to each other, each piston being reciprocable within a cylinder, a cam for reciprocating said pistons, a spill passage in each piston, a spill chamber formed in said housing, a sleeve element slidable axially on each piston to determine by its axial position the point in the stroke of the piston at which the spill passage therein will be placed in communication with the spill chamber, a rst part mounted Within said spill chamber and displaceable in a direction parallel to said axes, said first part being formed with a number of apertures each arranged to accommodate one of said sleeve elements with clearance, a flange formed on each of said elements of larger transverse dimensions than the corresponding aperture, a second part mounted in said spill chamber and displaceable in a direction parallel to said axes, a first abutment surface formed on said rst part to extend normal to said axes, a second abutment surface formed on said second part to extend parallel to said rst abutment surface, spacing means interposed between said rst and second abutment surfaces to maintain these latter in spaced parallel relationship, means for securing said first and second parts and said spacing means together to constitute a regulating member, a first locating surface formed on said flange and arranged to slidably engage said rst abutment surface, a second locating surface formed on said flange parallel to said first locating surface, said first and second locating surfaces being spaced apart in a direction parallel to said axes by a distance not greater than the height of said spacing means in the same direction, said sleeve elements being held against displacement relative to said member in a direction parallel to said axes by engagement of said first locating surface with said first abutment surface and said second locating surface with said second abutment surface respectively whilst being capable of adjusting themselves in a direction normal to said axes by said first locating surface sliding over said first abutment surface and said second locating surface sliding over said second abutment surface respectively.

WILLIAM FRIEDLANDER.

References Cited in the le of this patent UNITED STATES PATENTS 

